Sprocket wheel and chain.



No. 684,786. Patented Oct. 22, I901. .1. J. BREACH.

SPBDGKET WHEEL AND CHAIN.

(Application filed 0m 18, 1900. (No Model.) 2 Sheets-sheaf I.

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No. 684,786. Patented Oct. 22, I901.

J. J. BREACH.

SPRUOKET WHEEL AND CHAIN.

(Application filed Oct. 18, 1900.) (N9 Modal.) 2 Sheais-$hoet 2.

15 IV I y I I l.

UNITED- STATES PATENT OFFICE.

JAMES J. BREACH, OF BOSTON, MASSACHUSETTS.

SPROCKET WHEEL AND CHAIN.

SPECIFICATION forming part of Letters Patent No. 684,786, dated October 22, 1901.

Original application filed July 14, 1900, Serial No. 23,699. Divided and this application filed October 18, 1900. Serial No. 33,482. (No model.)

T0 on whom it may concern:

Be it known that I, JAMES J. BREACH, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and useful Improvements in Sprocket Wheels and Chains; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to sprocket wheels and chains.

Among the objects of my invention are to provide a chain which will always keep taut regardless of any stretch or wear in the chain, to provide a chain adjustable as to length to fit any path to be traversed by the chain, and to provide a sprocket wheel and chain the engaging portions of which willintermesh regardless of the length of the chain or of variations in its pitch due to wear or other causes.

With the above and other objects in view my invention consists in the devices and combinations of devices hereinafter described and claimed.

The embodiment of my invention disclosed in this application is the same as that disclosed in my pending application, Serial No. 23,599, filed July 14, 1900, of which this application is a division, and in which the chain is shown and describedas forming the guiding and actuating means for the knife-carriers of a sole-cutting machine. It is to be understood, however, that my present invention might be otherwise embodied and is not limited to such use, but may be used in any machine or device to perform any desired function.

In the drawings accompanying this application, Figure 1 is a sectional plan view on the line 1 l of Fig. 2, showing a preferred embodiment of my improved sprocket wheel and chain, the chain being arranged, as in my pending application, to form the guiding and actuating means for the knife-carriers of a sole-cutting machine. Fig. 2 is a longitudinal sectional view of the mechanism shown in Fig. 1, together with a portion of the ma chine-frame and the parts by which the sprocket wheel and chain are supported. Fig.

3 is a plan view, partly in section, of the sprocket-wheel and a portion of the chain. Fig. 4 is a sectional view on the line 44, Fig. 3. Fig. 5 is a detail plan view of the tension and take-up device for the chain, a portion of the casing being broken away; and Fig. 6

is a sectional view on the line 6 6, Fig. 5.

Referring to the drawings, in which like characters of reference indicate like parts, J represents one of two guide-rails supported from the frame A of the machine, and J J two blocks adjustably supported in guideslots cut in the inner surface of said rails. The block J has journaled therein a short vertical shaft J carrying at its lower end a sprocket-wheel K and at its upper end a worm-gear J meshing with a worm J 5 on a driving-shaft J. The block J carries at its lower side a triangular platej, secured thereto by means of a set-screwy" and having journaled at its corners, by means of suitable studs extending upwardly into the plate, chain-guiding rolls 1 7' j". Passing over the sprocket-wheel K and the rolls 9' j j is a chain L, herein shown as comprising two sections the ends of which are connected to frames I, as will be hereinafter described, so that the frames travel with the chain and in effect constitute a part thereof. As in the application hereinbefore referred to,the chain constitutes the guiding and actuating means for the knife-carriers of a sole-cutting machine, the path traveled by the chain being of the same general shape as the article to be cut out.

In the drawings an arm D, which forms a part of the frame upon which a knife-carrier is mounted, is shown connected to each'frame I, so as to be actuated thereby, the connection between the arm and the frame consisting of a stud t', secured to the bottom of the frame by a screw 1', upon which the end of the arm D is pivotally mounted. The pivot pins or studs 2' for the arms D are in a direct line with the portions of the chain leading from the frames I, so that the pivotpins and the ends of the arms D, mounted thereon, travel in a path corresponding to that of the: chain. In order to confine the pivots of the arms D to a certain fixed path and to prevent deviation therefrom on account of the flexibility of the chain, a guide- 1 any stretch or wear in the chain or any change roll t the axis of which coincides with the axis of the pivot-pin i, is mounted on the upper plate of each of the frames I, and fixed guides are provided to cooperate with the guide rolls. These guides consist of the plate j, against which the roll 1? bears while passing around the plate, internal side guides M, secured to and extending between the blocks J J (see Fig. 1,) and external side guides N, secured to the bottom of the guiderails J. (See Fig.2.) In passing around the large sprocket-wheel K the chain is supported by the face of the wheel, and no guide for the roll 2' is found necessary. The

blocks J J can be adjusted toward and from each other to vary the shape of the path traveled by the chain, and in order to preserve the continuity of the internal guides M for the roll when the blocks J J are adjusted these guides are composed of sections m m and m, the sections on being secured to the under side of the blocks J J and the sections m being mounted to slide in the lower sides of the sections m m. (See Fig. 1.) Pins m on the sections on m, extending into a slot cut in the upper side of the section 922, prevent the endwise separation of the sections on m, and a pin m extending upward from the middle point of the section m, prevents said section from being abnormally displaced from its central position by striking against the ends of the sections m on. As the blocks J J are moved from one position to another the length of the path traveled by the chain will be altered, and to allow for corresponding variations in the length of the chain I provide a chain tension and take-up device which will now be described. Each frame I carries two spring-barrels i loosely journaled on studs 1', extending between the upper and lower plates of the frame I, and to the outer surface of each barrel one end of a chain L is attached. A spiral spring is contained within each barrel, one end being secured to the barrel and the other to the stud '5 To prevent the stud from turning under the tension of the spring, a flange is formed on the upper end of the stud, and secured to said flange by means of a screw i is a block 1 extending upwardly through a slot in the upper plate of the frame I. The lower ends of the barrels t' are provided with intermeshing gears i whereby the barrels move in unison to take up or let off equal amounts on both sections of the chain. The chain is guided in its passage from the frame I by guide-rolls i, so situated that the line formed by the two sections of the chain passes through the axis of the guideroll 2' and pivot 11.

By the above-described construction it will be seen that the chain automatically adjusts itself to the length of the path to be traversed, always corresponding in length to the length of the path and remaining taut regardless of in the adjustment of the blocks J J As the blocks J J are adjusted to different positions it will be evident that the length of the chain passing over the sprocket-wheel K and guiderolls j j j may not always be an exact multiple of the length of a link. It will also be evident that if the chain stretches or wears the pitch of the chain will be altered. An ordinary sprocket-Wheel having teeth of uniform pitch cannot be used to drive such a chain satisfactorily, and I have accordingly devised an improved form of sprocket-wheel which is adapted to engage and drive a chain whether its length is an exact multiple of the length of a link or not and regardless of Variations in the pitch of the chain due to wear or other causes. One form of this sprocketwheel is illustrated in Figs. 3 and 4, wherein is shown a sprocket -wheel provided with yielding teeth arranged to be depressed be- -low the rim of the wheel and spaced at varying distances apart. As shown, the teeth consist of beveled projections on blocks 70, seated in radial recesses in the wheel K and pressed outwardly by springs 7;, surrounding stems k projecting inwardly from the blocks. The springs are seated in the recesses and bear against the inner side of the blocks, the outward movement of the blocks being limited by laterally-projecting pins 71: on the inner ends of the stems k engaging slots 75 in the wheel K. The teeth are preferably irregularly spaced about the periphery of the wheel and are also preferably so arranged that the distance between successive teeth in a group increases from the first to the last tooth in the group. The five teeth at the upper righthand side of Fig. 3 are shown so arranged. The teeth of the sprocket-wheel are adapted to engage notches in the chain L, formed by the intervals between the blocks land by recesses cut in the inner face of each block Z. These notches are preferably spaced at uniform distances apart to give the chain a definite pitch, although it will be evident that they might be irregularly spaced, in which case the teeth of the sprocket-wheel could be spaced at uniform distances apart, if desired.

The manner in which the chain is engaged and driven by the teeth of the sprocket-wheel Will be evident from an inspection of Fig. 3, in which certain of the teeth are shown in engagement with the notches in the chain and others depressed, so that the chain rides on the face of the wheel. The teeth are so arranged that a sufficient number will always engage the notches of the chain to drive it notwithstanding changes in the length or pitch of the chain.

While I have illustrated and described a chain formed of two sections with tension and take-up devices interposed between the ends of the sections, it is to be understood that other means might be employed to allow the chain to adjust itself to the length of the path to be traveled thereby without departing from the spirit of my invention. It is also to be understood that the construction illustrated in the drawings embodies my invention in its preferred form only and that the invention mightbe embodied in many different constructions without departing from the spirit thereof.

Having thus described my invention, I claim as new and desire to secure by Letters Patent of the United States 1; The combination with a sprocket-wheel, of a chain, a tension and take-up device carried bysaid chain for-causing the length of the chain to correspond to the length of the path to be traversed, said sprocket wheel and chain being provided with engaging portions constructed and arranged to intermesh regardless of variations in the pitch of the chain, substantially as described.

2. The combination with a sprocket-wheel, of a chain consisting of one or more chain,- sections, one or more frames, and one or more spring barrels mounted in each frame to which the ends of the chain-sections are connected, said sprocket wheel and chain being provided with engaging portions constructed and arranged to intermesh regardless of variations in the pitch of the chain, substantially as described.

3. The combination with a s procket-wheel, of a chain, a device carried thereby for causing the length of the chain to correspond to the length of the path to be traversed, sa1d sprocket wheel and chain being provided with engaging portions constructed and arranged tointermesh regardless of variations in the pitch of the chain, substantially as described.

4. A sprocket wheel and chain, the engaging portions of one of which are irregularly spaced, and one of which'parts is provided with yielding engaging portions, substantially as described.

5. A sprocket-wheel provided with irregu larly-spaced yielding teeth, substantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

JAMES J. BREACIL \Vitnesses:

FRED O. FISH, CHRISTIANA KITOHING. 

